Submission #301761

#	Time	Username	Problem	Language	Result	Execution time	Memory
301761		CSQ31	Boat (APIO16_boat)	C++14	31 / 100	574 ms	524292 KiB

boat

#pragma GCC optimize("Ofast") 
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) a.size()
#define all(a) a.begin(),a.end()
#define lb lower_bound
#define ub upper_bound
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
#define MOD (ll)(1e9+7)
#define INF (ll)(1e18)
#define debug(...) fprintf(stderr, __VA_ARGS__),fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false);\
debug("%s time : %.4fs\n", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))
typedef long long int ll;
typedef long double ld;
typedef pair<ll,ll> PII;
typedef pair<int,int> pii;
typedef vector<vector<int>> vii;
typedef vector<vector<ll>> VII;
ll gcd(ll a,ll b){if(!b)return a;else return gcd(b,a%b);}
const int MAXN = 1e6+1e5;
ll bit[MAXN];
void upd(int pos,ll val){
	for(int i=pos;i<MAXN;i+=i&(-i)){
		bit[i]+=val;
		bit[i]%=MOD;
	}
}
ll query(int pos){
	ll res=0;
	for(int i=pos;i>0;i-=i&(-i)){
		res+=bit[i];
		res%=MOD;
	}
	return res;
}
ll a[550];
ll b[550];
int main()
{
	int n;
	cin>>n;
	vector<ll>coords;
	for(int i=1;i<=n;i++){
		cin>>a[i]>>b[i];
		for(int j=a[i];j<=b[i];j++)coords.pb(j);
	}
	int sz = coords.size();
	sort(all(coords));
	coords.resize(unique(all(coords))-coords.begin());
	map<int,int>mp;
	//cout<<sz<<'\n';
	for(int i=0;i<sz;i++){
		mp[coords[i]] = i+1;
	}
	ll ans = 0;
	for(int i=1;i<=n;i++){
		for(int j=b[i];j>=a[i];j--){
			int p = mp[j];
			ll res = query(p-1);
			res%=MOD;
			upd(p,res+1);
		}
	}
	for(int i=1;i<=sz;i++){
		ans+=query(i)-query(i-1);
		ans%=MOD;
	}
	cout<<ans%MOD;;
}

• Subtask 1: 9 / 9
• Subtask 2: 22 / 22
• Subtask 3: 0 / 27
• Subtask 4: 0 / 42